Vertical break disconnecting switch



April 19, 1932. A. ALSAKER ET AL 1,854,441

VERTICAL BREAK DISCONNECTING SWITCH Filed Jan. 10. 1950 :s Sheets-Sheet1 April 19, 1932. A. ALSAKER ET AL 1,354,441

VERTICAL BREAK DISCONNECTING SWITCH Filed Jan. 10, 1950 s Shee ts-Sheet2 A. ALSAKER ET AL VERTICAL BREAK DISGONNECTING SWITCH Filed Jan. 10,1950 3 Sheets-Sheet 3 April 19, 1932.

Wed gkaker' weZdan H ZOZZ C72az-Z'e5 @471 oerrzez" Patented Apr. 19,1932 UNITED STATES PATENT OFFICE ALFRED WELDON O. HAMPTON, AND CHARLESA. KOERNEB, OF CHICAGO, ILLINOIS, LSSIGNOBS TO THE DELTA-STAB ELEUIRIOGOIPANY, OF CHICAGO,

ILLINOIS, A. CORPORATION OF ILLINOIS VERTICAL BREAK DISGONNEUIING SWITCHApplication filed January 10, 1930. Serial No. 419,776.

This invention relates to disconnect switches, and more particularly tosuch switches as are adapted for outdoor use, and preferably gangoperation.

Switches of the kind here contemplated generally comprise a supportingbase which 1s preferably grounded and upon which is mounted a contactsupporting insulator and one or more switch blade supportin or actu- 1ating insulators. In some types switches the contact supportinginsulator is rotatable while in other types it is stationary. Withincreasing voltages the required spacing of the contact and the bladefrom one another and the spacing of both from the supporting basebecomes very great. The insulators may be more than eight feet long andthe blade may be more than twelve feet long. The insulator stacks aregenerally made of porcelain or other fran 'ble material and thereforeare not able to withstand high stresses, especially in bending.Disconnect switches are infrequently operated, being required to standrhaps for years in a given position, during 5 which time they areexposed to all sorts of adverse weather. While the switch is closed thecontact and the end of the switch blade in engagement therewith maybecome corroded together. They may also become covered with sleet orice. The difliculty of swinging a blade overtwelve feet long and mountedon an insulator over eight feet long, when the free end of the blade isheld to its contact by ice, sleet and corrosion may be readilyappreciated. Unless means is provided to break the hind between theblade and the contact any turning efiort applied to the blade actuatinginsulator may cause crackingl of the insu ator. In the prior art with wich we are familiar this has been done by exerting either a longitudinalor a twisting motion to the blade prior to the swinging thereof awayfrom the contact. This is not quite satisfactory in that it inducescertain cantilever or bending stresses in the blade actuating insulator.In addition, if the bind between the blade and the contact is strong thecontact may be drawn with the blade in its longitudinal movement thuscausing bending and possible cracking of the contact supportinginsulator. Other forms of ice breakin movements have been developedwherein t e contact as well as the blade are actuated to break the hindbetween them. These constructions of the past have been such thatbending of the contact supporting insulator is not avoided in the eventthat the parts are rigidly frozen together thereby again subjecting theisulator to the danger of cracking.

It is one of the objects of the present invention to provide a highvoltage disconnect switch having a powerful ice breaking movement andwherein the bending stresses in the insulators are reduced to a minimumor entirely eliminated. This is accomplished in one embodiment of ourinvention by making the contact suporting insulator rotatable andproviding engagement between the contact and the blade on the oppositesides of the axis of rotation of the contact. To open the switch thecontact is first turned so as to twist the same free of an bind betweenit and the blade, and then the lads is swun to the open position. Due tothe fact that t e contact is engaged by the blade on the opposite sidesof its axis of rotation the bending stress in the contact su portinginsulator is eliminated. During t is ice breaking movement the switchblade may be maintained stationary or it may be given a slightreciprocating or oscillating movement to assist in breaking the hindbetween it and the contact.

The contacts are preferably of the pressure area type. The design issuch as to obtain as much contact area as possible. When this is donethe pressure need not be tremendously high in order to carry say 600amperes continuously. The contacting ends of the blade and contact areso constructed as to relieve the pressure between them when the contactis rotated to open the switch, thereby relieving the switch blade andits supporting insulator of the stress otherwise incident to theovercoming of this pressure when the switch is to be opened. The contactdesign is such that the full contact area and pressure will be obtainedeven though lost motion should develop in the operating mechanism. Thisis accomplished, in the embodiment herein illustrated, by making one ofthe contact engaging portions in the form of a prong which is adapted toembrace the other contact after which one of the contacts is twisted orturned into firm engagement with the other. As shown the prong ismounted at the end of the switch blade and is adapted to receive itscooperating contact between its tines. Th's may be reversed withoutdeparting from the spirit or scope of the present invention. Our contactconstruction is novel per se and constitutes a distinct improvement overthe prior art. Arcing horns are provided, the construction being suchthat the horns l kewise function as guides for the switch blade. Anauxiliary horn is provided for preventing arcing to the switch stop whenthe switch opening movement is initiated.

The attainment of the above and further objects of the present inventionwill be apparent from the following specification taken in conjunctionwith the accompanying drawings illustrating a preferred embodiment ofour invention.

In the drawings:

Figure 1 is a side view of a switch constructed in accordance with ourinvention;

Figure 2 is a fragmentary view showing the contacting end of the switch;

Figure 3 is a top plan view of the portion of the switch shown in Figure2;

Figure 4 is a diagrammatic view showing the manner of operationof theswitch operating crank;

Figure 5 is a similar diagrammatic view showing the correspondingoperation of the switch contact and of the switch blade.

Reference may now be had more particularly to Figure 1. The switch shownin this figure comprises a grounded supporting base 1 which may be of astandard construction and may comprise a air of channel members securedtogether in spaced relationship, the channels being outwardly facing.Two insulators 2 and 3 are mounted on the channel at one end thereof.The insulator 2 is stationary whereas the insulator 3 is rotatable, saidinsulator being mounted on the base 1 by means of suitable anti-frictionbearings 4 which may be of a construction such as shown in the pendingapplication of Alfred Alsaker, Serial No. 137,926, filed September 27,1926, althoughit is to be understood that any other preferred form ofbearings may be used if desired. The insulators 2 and 3 are ofsubstantially identical construction and comprise a number of petticoatinsulators well known in the art and secured together in the usualmanner. An actuating crank 5 (Figure 4) is secured to the rotatableportion of the insulator bearing 4 for rotating the same. This crank maybe of any desired construction. We prefer to use a crank such as isshown in the pending application 0 Alfred Alsaker and Elias G.Corneliussen, Serial No. 378,337, filed July 15, 1929, in that thispermits any desired angular adjustment of the crank with respect to theinsulator. Suitable electrostatic shields 6 and 7 are mounted upon theinsulators 2 and 3 for reasons well known in the art. The insulators 2and 3 are provided with a brace 9 for bracing one another. This brace 9extends between the bracket member 10 that is mounted upon the insulator2 and a member 11 upon the insulator 3, said bracket being journaled ina suitable bearing at the top of the member 11 in order to permitrotation of the insulator 3 with respect to the bracket member 9. Theconnecting bracing means 9 is here shown merely in diagrammatic formsince the same may be of any approved construction. If desired this maytake the form shown in the pending application of Alfred Alsaker,Thorsden Fjellstedt and Weldon 0. Hampton, Serial No. 350,708, filedMarch 28, 1929. A blade supporting member 15 in the form of a crank ispivoted on the bracket 10 at the ivot point 16 and is adapted to berotated a out the pivot 16 as an axis. The crank 15 is provided with asocket into which a tubular blade 17 is secured in the usual manner. Theblade is preferably a duraluminum drawn tube which is light in weightand which has a comparatively high conductivity. A counterweight 18 isadjustably secured to an arm that is secured to the crank 16 therebcounterbalancing the weight of the switc blade. A spindle 20 extendsthrough the hearing about which the bracket 9 is journaled, said spindlebeing a part of the portion 11 that is secured to the insulator 3 androtates therewith. A crank 21 is secured to the spindle 20 and isrotated thereby in a plane parallel to the base 1, and a connecting rod22 connects the crank 21 with the crank 15. The connecting rod 22 isconnected to the crank 21 by means of a universal joint 23 and isconnected to the crank 15 by means of a universal joint 24. The joint 24is made rather loose so as to permit a limited amount of play betweenthe connecting rod 22 and the crank 15 for a purpose which will beapparent as the description proceeds. It is to be noted that the cranks21 and 15 rotate in planes at right angles to one another. A terminallug 28, for receiving a line conductor, is secured to the bracket 9 andis connected to the switch blade 17 by means of a suitable, flexiblebraided copper conductor.

An insulator 30, which may be of any approved construction, is rotatablymounted upon the base 1 by means of a bearing 34 which may be of aconstruction similar to cured to the bearing 4 of the insulator 3. The

crank arms 5 and 35 are connected together by means of a connectingirod36. The rotating spindle portion of t e bearing 34 is extended below thebase 1 and is adapted to receive a crank 37, of a construction similarto the cranks 5 and 35, for rotating the same. The crank 37 is adaptedto be actuated, either by hand or by motor, in the usual manner in orderto actuate the switch. Upon actuation of the crank 37 the insulator 30is rotated and by means of the crank 35, the connecting rod 36, and thecrank 5 the insulator 3 is also rotated. The insulator 30 is providedwith an electrostatic shield 38 of a construction similar to the shields6 and 7 and rovided to reduce the concentration 0 electrostatic stressesat the end of the insulator, in a manner well known in the art. Agenerally cylindrical member 40 is secured to the top of the insulator35 by means of the usual form of insulator cap and has a ball bearingmember 41 mounted thereon. The ball bearing member 41 is rotatable withrespect to the cylindrical member 40 and is of the nonfreezing type. Aclam 42 is secured to the outer sleeve of the bearing 41 by means of aset of bolts indicated at 43, which bolts may constitute a swivel forthe clamp. This clamp is rigid with the outer portion of the bearing 41and is provided with a spilt sleeve 45 which is adapted to receive aline conductor 46 to anchor the same, said split sleeve being adapted tobe clamped to the end of the line conductor 46 by means of a number ofbolts 47 Upon rotation of the rotary insulator 30 the portion 40, whichconstitutes the. rotatable portion of the bearing 41 is rotated, theouter sleeve of the bearing 41 remaining stationary and serving as ananchor for the line conductor 46. An auxiliary arcing horn 50 is alsosecured to the member 42 by means of bolts 51. A stop 44 is formedintegral with the outer s eeve of the bearing 41 and is provided with ann standing arm which constitutes a sto for t e switch blade.

contact and arcing horn assembly 55 is mounted upon the inner portion ofthe bearign 41, that is upon the portion of the hearing that rotates asa unit with the insulator 35. This assembly comprises a contactingportion 56, which is of a generally I shaped cross-section in horizontalsection, and a horn and uide portion 57 merging therewith. A exiblebraided conductor 59 connects the contact portion 56 with the bracketmember 42 and the line conductor 46.

The switch blade 17 has a forked or pronged contact secured thereto andadapted to cooperate with the contact 56. Both of these contacts aremade of aluminum bronze reinforced with steel. The steel re inforcingrod of the contact 56 is indicated at 66. The forked contact 65 isprotecting l6 against arcing by means of the arcing prongs 68 and 69formed at the end thereof. Ball knobs 64 are also provided at the endsof the arcing prongs 68and 69 and at the end of the born 57.

The line conductor 46 that is connected to the contact 56 may beanchored directly to the clamp 45, as shown in Figure 2, or it may beanchored thereto indirectly being first secured to the base 1 of theswitch by means of an insulator indicated at 70 and the usual bracketconstructions.

A description will now be given of the manner of operation of the switchwhen the crank 37 is manipulated to open it and for this purposereference may be had to Figures 4 and 5 which show the position of thevarious operating cranks when the switch is closed. To open the switchthe crank 37 is rotated to rotate the insulator 30. The rotation is in acounter-clockwise direction, as seen in Figure 4. The insulator 30 isrotated so as to rotate the crank 35 from the position indicated at a tothe position indicated at g. At the commencement of operation thevarious parts are in the position indicatedby the letter a.

Upon the initial movement of the crank 35 from the position a to theposition b the crank 5 is moved in a clockwise direction by theconnecting rod 7 thereby moving from the position indicated at a to theposition indicated at b. When the crank 35 reaches the position b it isalmost in alignment with the connecting rod 7 and further rotation ofcrank 35 produces very little movement of the crank 5. As the crank 35moves from the position b to the position 0 it passes out of alignmentwith the connecting rod 7 and causes the crank 5 to change its directionof rotation and it now commences to move in a counter-clockwisedirection. When the end of the crank 35 reaches the successive positionindicated at 0, d, e and f the end of the crank 5 reaches the positionindicated by the corresponding letters. In Figure 5 we have indicatedthe position of the actuating end of the crank 21 and of the actuatingend of the connecting rod 22 corresponding to the positions a to g,respectively,of Figure 4, said positions being given correspondingreference letters. It must be remembered that the crank 21 rotates withthe insulator 3 as a unit being keyed thereto, hence the motion of thecrank 21 will be identical with the motion of the end of the crank 5.Thus the crank 21 moves first in a clockwise direction from its initialposition a to the position 5, and thereafter moves in a counterclockwisedirection from the position b to left as seen in Figure 5. Upon reversalof the position g. Upon the initial movement direction of rotation ofthe crank 21 from the position b to the position 0 the end of theconnecting rod that is connected to the crank 15 is moved to the rightas seen in Figure 5, said motion being also a very slight amount. At theposition a the crank 21 and the connecting rod 22 are almost inalignment and therefore the continued movement of the crank 21 producessubstantially no effect upon the remote end of the connecting rod 22. Itis to be noted that while the crank 21 is moving from position a to theposition b and from the position 6 toward the position a that the crank35 and the connecting rod 7 are passing through their position ofalignment, hence the movement imparted by the crank 35 to the crank 21is very slight. As the crank 35 passes from the position b to theposition 0 the crank 21 and the connecting rod 22 approach alignment,hence the amount of motion imparted to the connecting rod 22 at thistime is also very slight. Continued rotation of the crank 21 beyond theposition 0 causes it to pass dead center with the crank 22 andthereafter the rotation of the crank 21 brings about a movement of theend of the connecting rod 22 that is connected to the crank 15 saidmovement bein in a direction toward the left, as seen in igure 5. It maybe seen from this figure that during the interval taken for the crank 35to travel from the position a to the position 03 that the joint 24 ismoved a very slight amount, the motion being first slightly to the left,then to the right, and then back to the left. Upon movement of the crank35 from the position d to the final full open position indicated at gthe knuckle 24 is moved to the corresponding position indicated inFigure 5. The motion of the crank 35 from the position a to the positiond is the ice-breaking movement. During this interval the contact 56 ismoved from the position indicated at a to the position indicated at 6thereby bringing it substantially out of contact with the ronged portion65. It is to be noted that tile contact is rotated about its centerwhich is also the center of the rotating insulator stack 30 and that thecontact 56 is engaged by the prongs of the contact on the opposite sideof the axis of rotation of the insulator 30. Since the pronged contact65 is substantially stationary during this movement the insulator 30produces a powerin] twisting effect tending to loosen the contact 56from the contact 65. During this time there is no force tending to bendthe insulator 30, hence the insulator is free of cantilever stresses.Upon movement of the rotary insulator 30 from the position d to theposition 9 the switch blade 17 is rotated in a vertical plane about itsaxis 16. During the initial switch opening movement the auxiliary arcinghorns 50, which are stationary, maintain contact with the prongs 68 and69 and thereby prevent arcing between the contact 56 and the contact 65.As the switch blade is swung out of engagement with the contact and outof engagement with the arcing horns 50 any circuit that is to beinterrupted is interrupted between the arcing prongs 68 and 69 and themain arcing horn 57 that is mounted upon the insulator 30.

To close the switch the crank 37 is rotated in the opposite direction tomove the crank 35 from the position indicated at g to the positionindicated at a. During the initial movement of the actuating insulator,that is during the movement from the position g to the osition d theswitch blade 17 is swung rom its full open position, indicated in dottedlines in Figure 1, to substantially its full closed position indicatedin that figure. The contact 56 is now in the position d and upon furtheractuation of the insulator 30 it is rotated to the position 0, therebyengaging the contact 65 with a powerful camming action to secure firmelectrical engagement therewith. As previously pointed out, the joint 24between the connecting rod 22 and the crank 15 is made rather loose inorder to permit a limited amount of free play at that point. Thisprevents binding of the blade 17 against the stop 44.

Attention is called to the fact that the prong 65 at the end of theswitch blade 17 is provided with a rather large contacting surface. Fullcontact will be obtained between it and the contact 56 even thoughconsiderable looseness or lay should develop between the crank 35 an theswitch blade 17, that is anywhere between the crank 35 and theconnecting rod 36, or the connecting rod 36 and the crank 5, or betweenthe crank 21 and the connecting rod 22, or at any of the hinges. Thecontact 56 is relatively short and it is driven directly by theoperating mechanism and does not depend upon motion transmitted theretofrom the switch blade actuating stack. This is a considerableimprovement over the prior art in that play may be permitted in theswitch blade operating mechanism due to the fact that there is a ratherlong contacting surface carried by the blade for engagement by thecontact 57. However, if the blade actuating insulator were directlyconnected to the operating mechanism and if the insulator actuating thecontact 56 were actuated from the insulator 3 then any play that mightdevelop in the connection would result in a failure of the contact 56establishing firm electrical engagement with the contact 55. This is dueto the fact that if, due to play, the contact 56 upon closing shouldstop in the position 6 rather than in position a poor electricalengagement would be obtained, whereas if the switch blade 17 were tostop in its position 6, upon closing, due to play or lost motion thatmay develop in the connection then good electrical engagement wouldnevertheless be obtained.

It is to be noted that by arranging the cranks 35 and 21 so that theypass through their positions of alignment with their respectiveconnecting rods at substantially the same time or rather in quicksuccession we have obtained what corresponds to a usual lost motionconnection since the actuating end of the connecting rod 22 has only avery slight motion during the movement of the crank 35 from the positiona to the position d. If desired, enough play or looseness may be allowedin the knuckle 24 so that the switch blade remains entirely stationaryduring the turning of the crank35 from the position a to the position(1.

Aluminum bronze is suggested for at least one of the cooperating switchcontacts because of its hardness and resistance to wear, also because ofits springy quality and resistance to corrosion. The fork is preferablyof aluminum bronze since it must take most of the strain not onlybecause of the contact action but also due to its sliding against thearcing horn. The rotating contact may be made of hard drawn copper ifdesired. If both the fork and the contact were made of copper thefriction between them would be considerable not only due to theincreased coeflicient of friction, but mainly because of the bindinaction of the two films of copper oxide. ile the use of aluminum bronzecontacts is preferred we do not wish to be limited to its use as copperor other metals may also be used.

In compliance with the requirements of the patent statutes we haveherein shown and described a preferred embodiment of our invention. Itis, however, to be understood that the invention is not limited to theprecise instruction herein shown, the same being merely illustrative ofthe invention. What we consider new and desire to secure by LettersPatent is:

1. The method of separating a switch blade from its contact whichcomprises, turning the contact about a short radius and at the same timeproducing a slight reciprocating movement of the end of the blade thatis in engagement with the contact to break the hind between the contactand the blade, and then actuating the blade to the full open position.

2. A switch comprising a rotatably mounted contact and a switch blademovable into engagement with the contact on the opposite sides of theaxis of rotation of the contact, an axially rotatable insulatorsupporting and actuating the contact, and a stationary insulator and anaxially rotatable insulator supporting and actuating the switch blade.

3. A switch comprising a rotatably mounted contact, a switch blademovable into engagement with the contact on the opposite sides of theaxis of rotation of the contact, and means for actuating the contact inad vance of an appreciable actuation of the blade durin the switchopening movement, and means or actuating the blade, said last meanscomprisin a crank and a connectin rod and a secon crank and connecting rdriven by the first crank and connecting rod, both cranks and theirconnecting rods passing through their dead center positions upon theinitial switch opening operation to delay the opening movement of theblade.

4. A switch comprising a blade pivoted at one end, a contact adapted tobe engaged by the free end thereof, means adjacent the pivot of theblade for actuating the blade, and means for first oscillatin said firstnamed means to tend to loosen t e o posite end of the blade from thecontact, an then to swing the blade away from the contact. a

5. .A switch comprising a pair of rotatable insulators, means orrotating one of the insulators, a lost motion connection between saidinsulators, said lost motion connection including a crank and aconnecting rod and a second crank and connecting rod driven by the firstcrank and connecting rod, said cranks and connecting rods passingthrough their dead center positions at substantially the same time, aswitch contact mounted on on of the insulators and rotated thereby, anda switch blade movable by the other insulator into and out of positionfor engaging said contact.

6. A switch com rising a contact anda switch blade movab e into and outof contact making engagement with one another, means for actuating thecontact, means for actuating the blade, and a common actuating means forboth of said means, there being a lost motion between the commonactuating means and the switch blade actuatin means.

7. A switch inclu ing a movable switch blade, a contact at the endthereof, a second contact adapted to be enga ed by the first contact andbe wedged into rm engagement therewith, an insulator stack supportingthe a second contact, means for actuating the second contact to loosenthe engagement between the two while the switch blade is maintainedsubstantiall stationary, and means for thereafter swinging said switchblade away from said second contact in a direction initiallysubstantially axially of the insulator stack.

8. An electric switch comprising a pair of substantially parallel rotaryinsulators each rotatable about its central axis, and cooperatingcontacts actuated by the respective insulators, one of the contactsbeing rotated about the axis of rotation of its insulator and the otherbeing rotated about an axis at an angle to the axis of rotation of itsinsulator.

9. An electric switch including a pair of crank arms, a connecting rodconnectin the two, one of the cranks constituting the riv- I m crank andthe other the driven crank, said driving crank having a normal switchopen position and a switch closed position, said driving crank andconnecting rod passing through dead center when moved from one of saidpositions to the other, and a second crank and connecting rod actuatedby said driven crank and passing through dead center at aproximately thedead center position of the 10 rivin crank and connectin rod.

10. n electric switch including a pair of crank arms, a connecting rodconnecting the two, one of the cranks constituting the driving crank andthe other the driven crank,

said driving crank having a normal switch open position and a switchclosed position, said driving crank and connecting rod passing throughdead center when moved from one of said positions to the other, and asecond crank and connecting rod actuated by said driven crank andpassing through dead center slightly after the first mentioned drivingcrank and connecting rod passing through their dead center position.

11. An electric switch including a pair of cooperating contacts, meansfor actuating one of the contacts, means including a crank and aconnecting rod and a second crank and a second connecting rod betweenthe actuating means of the first contact and said second contact foractuating said second contact, said cranks and their respectiveconnecting rods passin through dead center successively upon t eactuation of the switch.

12. An electric switch including a pair of cooperating contacts, meansfor actuatin one of the contacts, means including a cran' 'and aconnecting rod and a second crank and a second connecting rod betweenthe actuating 40 means of the first contact and said second contact foractuating said second contact, said cranks and their respectiveconnecting rods passing through dead center at substantially the sametime upon the actuation of the switch.

In witness whereof, we hereunto subscribe our names this 7th day ofJanuary, 1930.

ALFRED ALSAKER. WELDON O. HAMPTON. CHARLES A. KOERNER.

DISCLAIMER 1,854,441.Alfred Alsaker, Weldon 0. Hampton, and Charles A.Koerner, Chicago, VERTICAL BREAK DIBCONNECTING Swrrcn. Patent dated A r.19, 1932. Disclaimer filed January 6, 1936, by the assignee, The Detat-Star Electric, Company, the patentees joining and concurring. Herebyenters this disclaimer to that claim which is numbered 7 in said patent,and which is in the following words, to wit:

7. A switch including a movable switch blade,-a contact at the endthereof, a second contact adapted to be engaged by the first contact andbe wedged into firm engagement therewith, an insulator stack supportingthe second contact, means for actuatin the second contact to loosen theengagement between the two while the switch b ads is maintainedsubstantially stationary, and means for thereafter swinging said switchblade away from said second contact in a direction initiallysubstantially axially of the insulator stac [Qfiic'ial Gazette February4, 1.936.]

I m crank and the other the driven crank, said driving crank having anormal switch open position and a switch closed position, said drivingcrank and connecting rod passing through dead center when moved from oneof said positions to the other, and a second crank and connecting rodactuated by said driven crank and passing through dead center ataproximately the dead center position of the 10 rivin crank andconnectin rod.

10. n electric switch including a pair of crank arms, a connecting rodconnecting the two, one of the cranks constituting the driving crank andthe other the driven crank,

said driving crank having a normal switch open position and a switchclosed position, said driving crank and connecting rod passing throughdead center when moved from one of said positions to the other, and asecond crank and connecting rod actuated by said driven crank andpassing through dead center slightly after the first mentioned drivingcrank and connecting rod passing through their dead center position.

11. An electric switch including a pair of cooperating contacts, meansfor actuating one of the contacts, means including a crank and aconnecting rod and a second crank and a second connecting rod betweenthe actuating means of the first contact and said second contact foractuating said second contact, said cranks and their respectiveconnecting rods passin through dead center successively upon t eactuation of the switch.

12. An electric switch including a pair of cooperating contacts, meansfor actuatin one of the contacts, means including a cran' 'and aconnecting rod and a second crank and a second connecting rod betweenthe actuating 40 means of the first contact and said second contact foractuating said second contact, said cranks and their respectiveconnecting rods passing through dead center at substantially the sametime upon the actuation of the switch.

In witness whereof, we hereunto subscribe our names this 7th day ofJanuary, 1930.

ALFRED ALSAKER. WELDON O. HAMPTON. CHARLES A. KOERNER.

DISCLAIMER 1,854,441.Alfred Alsaker, Weldon 0. Hampton, and Charles A.Koerner, Chicago, VERTICAL BREAK DIBCONNECTING Swrrcn. Patent dated A r.19, 1932. Disclaimer filed January 6, 1936, by the assignee, The Detat-Star Electric, Company, the patentees joining and concurring. Herebyenters this disclaimer to that claim which is numbered 7 in said patent,and which is in the following words, to wit:

7. A switch including a movable switch blade,-a contact at the endthereof, a second contact adapted to be engaged by the first contact andbe wedged into firm engagement therewith, an insulator stack supportingthe second contact, means for actuatin the second contact to loosen theengagement between the two while the switch b ads is maintainedsubstantially stationary, and means for thereafter swinging said switchblade away from said second contact in a direction initiallysubstantially axially of the insulator stac [Qfiic'ial Gazette February4, 1.936.]

